/* * Copyright 2004 The WebRTC Project Authors. All rights reserved. * * Use of this source code is governed by a BSD-style license * that can be found in the LICENSE file in the root of the source * tree. An additional intellectual property rights grant can be found * in the file PATENTS. All contributing project authors may * be found in the AUTHORS file in the root of the source tree. */ #include <time.h> #include "webrtc/base/httpcommon-inl.h" #include "webrtc/base/asyncsocket.h" #include "webrtc/base/common.h" #include "webrtc/base/diskcache.h" #include "webrtc/base/httpclient.h" #include "webrtc/base/logging.h" #include "webrtc/base/pathutils.h" #include "webrtc/base/socketstream.h" #include "webrtc/base/stringencode.h" #include "webrtc/base/stringutils.h" #include "webrtc/base/thread.h" namespace rtc { ////////////////////////////////////////////////////////////////////// // Helpers ////////////////////////////////////////////////////////////////////// namespace { const size_t kCacheHeader = 0; const size_t kCacheBody = 1; // Convert decimal string to integer bool HttpStringToUInt(const std::string& str, size_t* val) { ASSERT(NULL != val); char* eos = NULL; *val = strtoul(str.c_str(), &eos, 10); return (*eos == '\0'); } bool HttpShouldCache(const HttpTransaction& t) { bool verb_allows_cache = (t.request.verb == HV_GET) || (t.request.verb == HV_HEAD); bool is_range_response = t.response.hasHeader(HH_CONTENT_RANGE, NULL); bool has_expires = t.response.hasHeader(HH_EXPIRES, NULL); bool request_allows_cache = has_expires || (std::string::npos != t.request.path.find('?')); bool response_allows_cache = has_expires || HttpCodeIsCacheable(t.response.scode); bool may_cache = verb_allows_cache && request_allows_cache && response_allows_cache && !is_range_response; std::string value; if (t.response.hasHeader(HH_CACHE_CONTROL, &value)) { HttpAttributeList directives; HttpParseAttributes(value.data(), value.size(), directives); // Response Directives Summary: // public - always cacheable // private - do not cache in a shared cache // no-cache - may cache, but must revalidate whether fresh or stale // no-store - sensitive information, do not cache or store in any way // max-age - supplants Expires for staleness // s-maxage - use as max-age for shared caches, ignore otherwise // must-revalidate - may cache, but must revalidate after stale // proxy-revalidate - shared cache must revalidate if (HttpHasAttribute(directives, "no-store", NULL)) { may_cache = false; } else if (HttpHasAttribute(directives, "public", NULL)) { may_cache = true; } } return may_cache; } enum HttpCacheState { HCS_FRESH, // In cache, may use HCS_STALE, // In cache, must revalidate HCS_NONE // Not in cache }; HttpCacheState HttpGetCacheState(const HttpTransaction& t) { // Temporaries std::string s_temp; time_t u_temp; // Current time size_t now = time(0); HttpAttributeList cache_control; if (t.response.hasHeader(HH_CACHE_CONTROL, &s_temp)) { HttpParseAttributes(s_temp.data(), s_temp.size(), cache_control); } // Compute age of cache document time_t date; if (!t.response.hasHeader(HH_DATE, &s_temp) || !HttpDateToSeconds(s_temp, &date)) return HCS_NONE; // TODO: Timestamp when cache request sent and response received? time_t request_time = date; time_t response_time = date; time_t apparent_age = 0; if (response_time > date) { apparent_age = response_time - date; } size_t corrected_received_age = apparent_age; size_t i_temp; if (t.response.hasHeader(HH_AGE, &s_temp) && HttpStringToUInt(s_temp, (&i_temp))) { u_temp = static_cast<time_t>(i_temp); corrected_received_age = stdmax(apparent_age, u_temp); } size_t response_delay = response_time - request_time; size_t corrected_initial_age = corrected_received_age + response_delay; size_t resident_time = now - response_time; size_t current_age = corrected_initial_age + resident_time; // Compute lifetime of document size_t lifetime; if (HttpHasAttribute(cache_control, "max-age", &s_temp)) { lifetime = atoi(s_temp.c_str()); } else if (t.response.hasHeader(HH_EXPIRES, &s_temp) && HttpDateToSeconds(s_temp, &u_temp)) { lifetime = u_temp - date; } else if (t.response.hasHeader(HH_LAST_MODIFIED, &s_temp) && HttpDateToSeconds(s_temp, &u_temp)) { // TODO: Issue warning 113 if age > 24 hours lifetime = static_cast<size_t>(now - u_temp) / 10; } else { return HCS_STALE; } return (lifetime > current_age) ? HCS_FRESH : HCS_STALE; } enum HttpValidatorStrength { HVS_NONE, HVS_WEAK, HVS_STRONG }; HttpValidatorStrength HttpRequestValidatorLevel(const HttpRequestData& request) { if (HV_GET != request.verb) return HVS_STRONG; return request.hasHeader(HH_RANGE, NULL) ? HVS_STRONG : HVS_WEAK; } HttpValidatorStrength HttpResponseValidatorLevel(const HttpResponseData& response) { std::string value; if (response.hasHeader(HH_ETAG, &value)) { bool is_weak = (strnicmp(value.c_str(), "W/", 2) == 0); return is_weak ? HVS_WEAK : HVS_STRONG; } if (response.hasHeader(HH_LAST_MODIFIED, &value)) { time_t last_modified, date; if (HttpDateToSeconds(value, &last_modified) && response.hasHeader(HH_DATE, &value) && HttpDateToSeconds(value, &date) && (last_modified + 60 < date)) { return HVS_STRONG; } return HVS_WEAK; } return HVS_NONE; } std::string GetCacheID(const HttpRequestData& request) { std::string id, url; id.append(ToString(request.verb)); id.append("_"); request.getAbsoluteUri(&url); id.append(url); return id; } } // anonymous namespace ////////////////////////////////////////////////////////////////////// // Public Helpers ////////////////////////////////////////////////////////////////////// bool HttpWriteCacheHeaders(const HttpResponseData* response, StreamInterface* output, size_t* size) { size_t length = 0; // Write all unknown and end-to-end headers to a cache file for (HttpData::const_iterator it = response->begin(); it != response->end(); ++it) { HttpHeader header; if (FromString(header, it->first) && !HttpHeaderIsEndToEnd(header)) continue; length += it->first.length() + 2 + it->second.length() + 2; if (!output) continue; std::string formatted_header(it->first); formatted_header.append(": "); formatted_header.append(it->second); formatted_header.append("\r\n"); StreamResult result = output->WriteAll(formatted_header.data(), formatted_header.length(), NULL, NULL); if (SR_SUCCESS != result) { return false; } } if (output && (SR_SUCCESS != output->WriteAll("\r\n", 2, NULL, NULL))) { return false; } length += 2; if (size) *size = length; return true; } bool HttpReadCacheHeaders(StreamInterface* input, HttpResponseData* response, HttpData::HeaderCombine combine) { while (true) { std::string formatted_header; StreamResult result = input->ReadLine(&formatted_header); if ((SR_EOS == result) || (1 == formatted_header.size())) { break; } if (SR_SUCCESS != result) { return false; } size_t end_of_name = formatted_header.find(':'); if (std::string::npos == end_of_name) { LOG_F(LS_WARNING) << "Malformed cache header"; continue; } size_t start_of_value = end_of_name + 1; size_t end_of_value = formatted_header.length(); while ((start_of_value < end_of_value) && isspace(formatted_header[start_of_value])) ++start_of_value; while ((start_of_value < end_of_value) && isspace(formatted_header[end_of_value-1])) --end_of_value; size_t value_length = end_of_value - start_of_value; std::string name(formatted_header.substr(0, end_of_name)); std::string value(formatted_header.substr(start_of_value, value_length)); response->changeHeader(name, value, combine); } return true; } ////////////////////////////////////////////////////////////////////// // HttpClient ////////////////////////////////////////////////////////////////////// const size_t kDefaultRetries = 1; const size_t kMaxRedirects = 5; HttpClient::HttpClient(const std::string& agent, StreamPool* pool, HttpTransaction* transaction) : agent_(agent), pool_(pool), transaction_(transaction), free_transaction_(false), retries_(kDefaultRetries), attempt_(0), redirects_(0), redirect_action_(REDIRECT_DEFAULT), uri_form_(URI_DEFAULT), cache_(NULL), cache_state_(CS_READY), resolver_(NULL) { base_.notify(this); if (NULL == transaction_) { free_transaction_ = true; transaction_ = new HttpTransaction; } } HttpClient::~HttpClient() { base_.notify(NULL); base_.abort(HE_SHUTDOWN); if (resolver_) { resolver_->Destroy(false); } release(); if (free_transaction_) delete transaction_; } void HttpClient::reset() { server_.Clear(); request().clear(true); response().clear(true); context_.reset(); redirects_ = 0; base_.abort(HE_OPERATION_CANCELLED); } void HttpClient::OnResolveResult(AsyncResolverInterface* resolver) { if (resolver != resolver_) { return; } int error = resolver_->GetError(); server_ = resolver_->address(); resolver_->Destroy(false); resolver_ = NULL; if (error != 0) { LOG(LS_ERROR) << "Error " << error << " resolving name: " << server_; onHttpComplete(HM_CONNECT, HE_CONNECT_FAILED); } else { connect(); } } void HttpClient::StartDNSLookup() { resolver_ = new AsyncResolver(); resolver_->SignalDone.connect(this, &HttpClient::OnResolveResult); resolver_->Start(server_); } void HttpClient::set_server(const SocketAddress& address) { server_ = address; // Setting 'Host' here allows it to be overridden before starting the request, // if necessary. request().setHeader(HH_HOST, HttpAddress(server_, false), true); } StreamInterface* HttpClient::GetDocumentStream() { return base_.GetDocumentStream(); } void HttpClient::start() { if (base_.mode() != HM_NONE) { // call reset() to abort an in-progress request ASSERT(false); return; } ASSERT(!IsCacheActive()); if (request().hasHeader(HH_TRANSFER_ENCODING, NULL)) { // Exact size must be known on the client. Instead of using chunked // encoding, wrap data with auto-caching file or memory stream. ASSERT(false); return; } attempt_ = 0; // If no content has been specified, using length of 0. request().setHeader(HH_CONTENT_LENGTH, "0", false); if (!agent_.empty()) { request().setHeader(HH_USER_AGENT, agent_, false); } UriForm uri_form = uri_form_; if (PROXY_HTTPS == proxy_.type) { // Proxies require absolute form uri_form = URI_ABSOLUTE; request().version = HVER_1_0; request().setHeader(HH_PROXY_CONNECTION, "Keep-Alive", false); } else { request().setHeader(HH_CONNECTION, "Keep-Alive", false); } if (URI_ABSOLUTE == uri_form) { // Convert to absolute uri form std::string url; if (request().getAbsoluteUri(&url)) { request().path = url; } else { LOG(LS_WARNING) << "Couldn't obtain absolute uri"; } } else if (URI_RELATIVE == uri_form) { // Convert to relative uri form std::string host, path; if (request().getRelativeUri(&host, &path)) { request().setHeader(HH_HOST, host); request().path = path; } else { LOG(LS_WARNING) << "Couldn't obtain relative uri"; } } if ((NULL != cache_) && CheckCache()) { return; } connect(); } void HttpClient::connect() { int stream_err; if (server_.IsUnresolvedIP()) { StartDNSLookup(); return; } StreamInterface* stream = pool_->RequestConnectedStream(server_, &stream_err); if (stream == NULL) { ASSERT(0 != stream_err); LOG(LS_ERROR) << "RequestConnectedStream error: " << stream_err; onHttpComplete(HM_CONNECT, HE_CONNECT_FAILED); } else { base_.attach(stream); if (stream->GetState() == SS_OPEN) { base_.send(&transaction_->request); } } } void HttpClient::prepare_get(const std::string& url) { reset(); Url<char> purl(url); set_server(SocketAddress(purl.host(), purl.port())); request().verb = HV_GET; request().path = purl.full_path(); } void HttpClient::prepare_post(const std::string& url, const std::string& content_type, StreamInterface* request_doc) { reset(); Url<char> purl(url); set_server(SocketAddress(purl.host(), purl.port())); request().verb = HV_POST; request().path = purl.full_path(); request().setContent(content_type, request_doc); } void HttpClient::release() { if (StreamInterface* stream = base_.detach()) { pool_->ReturnConnectedStream(stream); } } bool HttpClient::ShouldRedirect(std::string* location) const { // TODO: Unittest redirection. if ((REDIRECT_NEVER == redirect_action_) || !HttpCodeIsRedirection(response().scode) || !response().hasHeader(HH_LOCATION, location) || (redirects_ >= kMaxRedirects)) return false; return (REDIRECT_ALWAYS == redirect_action_) || (HC_SEE_OTHER == response().scode) || (HV_HEAD == request().verb) || (HV_GET == request().verb); } bool HttpClient::BeginCacheFile() { ASSERT(NULL != cache_); ASSERT(CS_READY == cache_state_); std::string id = GetCacheID(request()); CacheLock lock(cache_, id, true); if (!lock.IsLocked()) { LOG_F(LS_WARNING) << "Couldn't lock cache"; return false; } if (HE_NONE != WriteCacheHeaders(id)) { return false; } scoped_ptr<StreamInterface> stream(cache_->WriteResource(id, kCacheBody)); if (!stream) { LOG_F(LS_ERROR) << "Couldn't open body cache"; return false; } lock.Commit(); // Let's secretly replace the response document with Folgers Crystals, // er, StreamTap, so that we can mirror the data to our cache. StreamInterface* output = response().document.release(); if (!output) { output = new NullStream; } StreamTap* tap = new StreamTap(output, stream.release()); response().document.reset(tap); return true; } HttpError HttpClient::WriteCacheHeaders(const std::string& id) { scoped_ptr<StreamInterface> stream(cache_->WriteResource(id, kCacheHeader)); if (!stream) { LOG_F(LS_ERROR) << "Couldn't open header cache"; return HE_CACHE; } if (!HttpWriteCacheHeaders(&transaction_->response, stream.get(), NULL)) { LOG_F(LS_ERROR) << "Couldn't write header cache"; return HE_CACHE; } return HE_NONE; } void HttpClient::CompleteCacheFile() { // Restore previous response document StreamTap* tap = static_cast<StreamTap*>(response().document.release()); response().document.reset(tap->Detach()); int error; StreamResult result = tap->GetTapResult(&error); // Delete the tap and cache stream (which completes cache unlock) delete tap; if (SR_SUCCESS != result) { LOG(LS_ERROR) << "Cache file error: " << error; cache_->DeleteResource(GetCacheID(request())); } } bool HttpClient::CheckCache() { ASSERT(NULL != cache_); ASSERT(CS_READY == cache_state_); std::string id = GetCacheID(request()); if (!cache_->HasResource(id)) { // No cache file available return false; } HttpError error = ReadCacheHeaders(id, true); if (HE_NONE == error) { switch (HttpGetCacheState(*transaction_)) { case HCS_FRESH: // Cache content is good, read from cache break; case HCS_STALE: // Cache content may be acceptable. Issue a validation request. if (PrepareValidate()) { return false; } // Couldn't validate, fall through. case HCS_NONE: // Cache content is not useable. Issue a regular request. response().clear(false); return false; } } if (HE_NONE == error) { error = ReadCacheBody(id); cache_state_ = CS_READY; } if (HE_CACHE == error) { LOG_F(LS_WARNING) << "Cache failure, continuing with normal request"; response().clear(false); return false; } SignalHttpClientComplete(this, error); return true; } HttpError HttpClient::ReadCacheHeaders(const std::string& id, bool override) { scoped_ptr<StreamInterface> stream(cache_->ReadResource(id, kCacheHeader)); if (!stream) { return HE_CACHE; } HttpData::HeaderCombine combine = override ? HttpData::HC_REPLACE : HttpData::HC_AUTO; if (!HttpReadCacheHeaders(stream.get(), &transaction_->response, combine)) { LOG_F(LS_ERROR) << "Error reading cache headers"; return HE_CACHE; } response().scode = HC_OK; return HE_NONE; } HttpError HttpClient::ReadCacheBody(const std::string& id) { cache_state_ = CS_READING; HttpError error = HE_NONE; size_t data_size; scoped_ptr<StreamInterface> stream(cache_->ReadResource(id, kCacheBody)); if (!stream || !stream->GetAvailable(&data_size)) { LOG_F(LS_ERROR) << "Unavailable cache body"; error = HE_CACHE; } else { error = OnHeaderAvailable(false, false, data_size); } if ((HE_NONE == error) && (HV_HEAD != request().verb) && response().document) { char buffer[1024 * 64]; StreamResult result = Flow(stream.get(), buffer, ARRAY_SIZE(buffer), response().document.get()); if (SR_SUCCESS != result) { error = HE_STREAM; } } return error; } bool HttpClient::PrepareValidate() { ASSERT(CS_READY == cache_state_); // At this point, request() contains the pending request, and response() // contains the cached response headers. Reformat the request to validate // the cached content. HttpValidatorStrength vs_required = HttpRequestValidatorLevel(request()); HttpValidatorStrength vs_available = HttpResponseValidatorLevel(response()); if (vs_available < vs_required) { return false; } std::string value; if (response().hasHeader(HH_ETAG, &value)) { request().addHeader(HH_IF_NONE_MATCH, value); } if (response().hasHeader(HH_LAST_MODIFIED, &value)) { request().addHeader(HH_IF_MODIFIED_SINCE, value); } response().clear(false); cache_state_ = CS_VALIDATING; return true; } HttpError HttpClient::CompleteValidate() { ASSERT(CS_VALIDATING == cache_state_); std::string id = GetCacheID(request()); // Merge cached headers with new headers HttpError error = ReadCacheHeaders(id, false); if (HE_NONE != error) { // Rewrite merged headers to cache CacheLock lock(cache_, id); error = WriteCacheHeaders(id); } if (HE_NONE != error) { error = ReadCacheBody(id); } return error; } HttpError HttpClient::OnHeaderAvailable(bool ignore_data, bool chunked, size_t data_size) { // If we are ignoring the data, this is an intermediate header. // TODO: don't signal intermediate headers. Instead, do all header-dependent // processing now, and either set up the next request, or fail outright. // TODO: by default, only write response documents with a success code. SignalHeaderAvailable(this, !ignore_data, ignore_data ? 0 : data_size); if (!ignore_data && !chunked && (data_size != SIZE_UNKNOWN) && response().document) { // Attempt to pre-allocate space for the downloaded data. if (!response().document->ReserveSize(data_size)) { return HE_OVERFLOW; } } return HE_NONE; } // // HttpBase Implementation // HttpError HttpClient::onHttpHeaderComplete(bool chunked, size_t& data_size) { if (CS_VALIDATING == cache_state_) { if (HC_NOT_MODIFIED == response().scode) { return CompleteValidate(); } // Should we remove conditional headers from request? cache_state_ = CS_READY; cache_->DeleteResource(GetCacheID(request())); // Continue processing response as normal } ASSERT(!IsCacheActive()); if ((request().verb == HV_HEAD) || !HttpCodeHasBody(response().scode)) { // HEAD requests and certain response codes contain no body data_size = 0; } if (ShouldRedirect(NULL) || ((HC_PROXY_AUTHENTICATION_REQUIRED == response().scode) && (PROXY_HTTPS == proxy_.type))) { // We're going to issue another request, so ignore the incoming data. base_.set_ignore_data(true); } HttpError error = OnHeaderAvailable(base_.ignore_data(), chunked, data_size); if (HE_NONE != error) { return error; } if ((NULL != cache_) && !base_.ignore_data() && HttpShouldCache(*transaction_)) { if (BeginCacheFile()) { cache_state_ = CS_WRITING; } } return HE_NONE; } void HttpClient::onHttpComplete(HttpMode mode, HttpError err) { if (((HE_DISCONNECTED == err) || (HE_CONNECT_FAILED == err) || (HE_SOCKET_ERROR == err)) && (HC_INTERNAL_SERVER_ERROR == response().scode) && (attempt_ < retries_)) { // If the response code has not changed from the default, then we haven't // received anything meaningful from the server, so we are eligible for a // retry. ++attempt_; if (request().document && !request().document->Rewind()) { // Unable to replay the request document. err = HE_STREAM; } else { release(); connect(); return; } } else if (err != HE_NONE) { // fall through } else if (mode == HM_CONNECT) { base_.send(&transaction_->request); return; } else if ((mode == HM_SEND) || HttpCodeIsInformational(response().scode)) { // If you're interested in informational headers, catch // SignalHeaderAvailable. base_.recv(&transaction_->response); return; } else { if (!HttpShouldKeepAlive(response())) { LOG(LS_VERBOSE) << "HttpClient: closing socket"; base_.stream()->Close(); } std::string location; if (ShouldRedirect(&location)) { Url<char> purl(location); set_server(SocketAddress(purl.host(), purl.port())); request().path = purl.full_path(); if (response().scode == HC_SEE_OTHER) { request().verb = HV_GET; request().clearHeader(HH_CONTENT_TYPE); request().clearHeader(HH_CONTENT_LENGTH); request().document.reset(); } else if (request().document && !request().document->Rewind()) { // Unable to replay the request document. ASSERT(REDIRECT_ALWAYS == redirect_action_); err = HE_STREAM; } if (err == HE_NONE) { ++redirects_; context_.reset(); response().clear(false); release(); start(); return; } } else if ((HC_PROXY_AUTHENTICATION_REQUIRED == response().scode) && (PROXY_HTTPS == proxy_.type)) { std::string authorization, auth_method; HttpData::const_iterator begin = response().begin(HH_PROXY_AUTHENTICATE); HttpData::const_iterator end = response().end(HH_PROXY_AUTHENTICATE); for (HttpData::const_iterator it = begin; it != end; ++it) { HttpAuthContext *context = context_.get(); HttpAuthResult res = HttpAuthenticate( it->second.data(), it->second.size(), proxy_.address, ToString(request().verb), request().path, proxy_.username, proxy_.password, context, authorization, auth_method); context_.reset(context); if (res == HAR_RESPONSE) { request().setHeader(HH_PROXY_AUTHORIZATION, authorization); if (request().document && !request().document->Rewind()) { err = HE_STREAM; } else { // Explicitly do not reset the HttpAuthContext response().clear(false); // TODO: Reuse socket when authenticating? release(); start(); return; } } else if (res == HAR_IGNORE) { LOG(INFO) << "Ignoring Proxy-Authenticate: " << auth_method; continue; } else { break; } } } } if (CS_WRITING == cache_state_) { CompleteCacheFile(); cache_state_ = CS_READY; } else if (CS_READING == cache_state_) { cache_state_ = CS_READY; } release(); SignalHttpClientComplete(this, err); } void HttpClient::onHttpClosed(HttpError err) { // This shouldn't occur, since we return the stream to the pool upon command // completion. ASSERT(false); } ////////////////////////////////////////////////////////////////////// // HttpClientDefault ////////////////////////////////////////////////////////////////////// HttpClientDefault::HttpClientDefault(SocketFactory* factory, const std::string& agent, HttpTransaction* transaction) : ReuseSocketPool(factory ? factory : Thread::Current()->socketserver()), HttpClient(agent, NULL, transaction) { set_pool(this); } ////////////////////////////////////////////////////////////////////// } // namespace rtc